how to ad a panel in the properties/data Speaker specific
Add a poll method.
To narrow it down could look to see if context object is of type 'SPEAKER' or since it is in the properties space, there is a speaker context member available when the object is not a  speaker it will be none.
class HelloWorldPanel(bpy.types.Panel):
    &quot;&quot;&quot;Creates a Panel in the Object properties window&quot;&quot;&quot;
    bl_label = &quot;Hello World Panel&quot;
    bl_idname = &quot;OBJECT_PT_hello&quot;
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = &quot;data&quot;

    @classmethod 
    def poll(cls, context):
        return context.speaker is not None
    
    def draw(self, context):
        layout = self.layout

        obj = context.object

        row = layout.row()
        row.label(text=&quot;Hello world!&quot;, icon='WORLD_DATA')